Currently, as to electric tools at home and abroad, in order to change the rotation direction of a drill head of an electric drill, the electric drill in the prior art generally changes the direction of the electric current through a switch to reverse the rotational direction of a motor. This mode of operation has a number of problems.
Firstly, the motor and the switch tend to be relatively greatly damaged because they have to bear huge amount of reverse current, resulting in shortened service life.
Secondly, the manufacturing process of a forward and reverse motor is very complicated, and its electromagnetic interference is also great.
Thirdly, when the electric drill is changed from forward rotation to reverse rotation, it needs to be slowed down, stopped and reaccelerated. This tends to take relatively long time, resulting in low working efficiency.
Fourthly, the electric drill consumes a large amount of energy when it changes rotation direction, particularly when it is used to tap. The electric drill is frequently operated and thus may overheat and become damaged.
Regarding the problem of the electric drill due to changing its rotation direction, a novel electric drill needs to be a safe, environmentally-protecting and energy-saving product with time-saving and labor-saving advantages when its rotational direction is changed.